Table concentrator



Feb, 24, 1 925.

A. H. STEBBINS TABLE CONCENTRATOR Filed May 5 1923 4 Sheets-Sheet 2 Feb.

A. H. STEBBINS TABLE CONCENTRATOR Filed May 5.

1923 4 Sheets-Sheet 4 ATT'O FP/ EY Patented Feb. 24, 1925.

UNITED STATES ALBERT H. STEBBIITS, F LO'S ANGELES, CALIFORNIA.

mam oonomrraa'roa.

Application Medley 5, 1923. Serial No. 888,809.

.To all whom it may concern:

Be it known that I, ALBERT H. Srnsnms,

. a citizen of the United States, residing at Los Angeleain the county of Los An eles and State of California, have invente an Improvement in Table Concentrators, of which the following description, in connection with-the accompanying drawings, is a specification, like characters'on the drawings representing like parts.

This invention relates toconcentrators of the table type for the separation of ores and other materials in accordance with their differences in specific gravity.

Most metals or values have a higher specific gravity than the accompan ing im urities and are usually distribute throng out a relatively large amount of impurities or foreign matter, so that it is necessary to treat a large amount of material as compared with' the values obtainedtherefrom.

The present invention relates to the type of table concentrator which employs a transversely inclined deck surface having rifiies extending in an inclined direction over the deck surfaceand arranged to direct the heavier materials or values toward the upper side of the deck while the lighter materials or tailings pass over the top of the rifiles toward the lower side of the deck.

In concentrators of this type movement may be imparted to the deck to advance the materials being treated over-the surface of the same, and the movement imparted to the deck should be such that it will advance the materials progressively without disturbing the strata into which the materials are being separated. One important feature of the present invention, therefore, resides in novel means for imparting a back and forth movement to the deck for advancing the materials progressively along the deck surface.

.Separation of the materials into different strata or layers is promoted by passing air upwardly through the deck surface and the materials thereupon, and another feature of the invention resides in a novel disposition of the air delivering apertures formed in the deck surface.

Othenfeatures of the invention reside in improvements in the construction of the rililes, and in the deck surface for promoting launching the rifiles. Still other features of the invention reof the materials traveling along side in novel means for adjusting the deck to different inclinations and for clam ing the same in the'desired position of ad ustment, and in novel means fousupporting the deck for .back and forth movement- Other features of the invention and novel combination of parts in addition to the above will be hereinafter described in connection with the accopanying drawings which In the drawings: 7

Fig. 1 is a side elevation of a table concentrator constructed in accordance with the present invention, the deck cover being removed.

Fig. 2 is an enlar ed perspective view of p portion of the eck surface shown in Fig. 3, is a top plan view of the deck supporting and operating means, the deck liein removed.

ig. 4 is a side view of the deck and deck supporting frame, viewing the side opposite to that shown in Fig.

Fig. 5 is an enlar ed section l view taken on the line 5-5 of ig. '1.

. Fig. 6 is an enlarged vertical sectional k The table concentrator shown consists of a fixed frame 1() upon which the movable frame 11 ismounted, and upon the frame 11 is mounted a deck 12 having provisions for adjustment to different transverse inclinations upon the frame 1]..

The fixed frame 10 may be of rectangular configuration and is 'formed of longitudinally extendin side-rails 13, 14 and 15 se cured in space relation by uprights 16 andlaterally extending beams 17 The movable frame/11 is rectangular in plan view and consists of the longitudinally extending side bars 18 rigidly connected by the transversely extending beams 19, and

the upper laterally extending flanges 23, and

angle irons 24 L-shaped in cross section may be rigidly secured to the flanges 23. The deck 12 is secured to the movable frame 11 by hinges 25, and these hinges are shown as secured to the under face of the deck and to longitudinally extending strips 26 secured to the upstanding portion of the L-shaped angle irons 24.

It is desirable that means he provided for adjusting the deck 12 to different transverse inclinations to vary the flow of the materials laterally over the riffles toward the lower side of the deck, and that clamping mechanism be provided for rigidly securing the deck in the desired position of angular adjustment. In the construction shown an adjusting screw 27 and cooperating hand wheel 28 serve to adjust the deck to the desired transverse inclination upon the frame 11. The upper end of the screw 27 is seated in a socket formed in a block 29 secured to the under face of the deck 12 and the screw 27 extends downwardly into threaded engagement with the hand wheel 28 rotatably mounted on a transversely extending beam 19 of the frame 11. As the hand wheel 28 is rotated in one direction the deck will be rocked upwardly about the hinges 25, and when rotated in the opposite direction the deck will be rocked down: wardly.

The deck 12 as will be apparent from Figs. 1 and 8, tapers toward its material discharge end and the inclined bar 20 secured to the frame 11 is inclined at an angle corresponding to the taper of the deck 12, and after the deck has been adjusted to the desired transverse inclination it is clamped in this position of adjustment by brackets 21 extending upwardly from the bar 20 and cooperating brackets 30 extending downwardly from the under face of the deck 12. The

brackets 21 and 30 as best shown in Figs. 6

and"? are provided with elongated bolt-receiving slots 31 and 32 adapted to receive the clamping bolt 33. preferably is secured to the bar 20 in spaced relation to the bracket 21 to provide a space therebetween for the downwardly extending portion of the bracket 30, and the bolt 33 serves to clamp the bracket 30 between the brackets 21 and 34. The space between the spaced brackets 21 and 34 serves to receive an abutment block 35 upon which the lower end of the bracet 30 may rest to assist the clamping bolt in supporting the weight of the deck.

As stated the deck supporting frame 11 A flexible bracket 34 throw movement is imparted to the materials upon the deck as the movement of the deck is arrested in the material advancing direction. In the present case the under-throw type of mounting is employed, and crank rocker shafts 36 extending transversely across the fixed frame 10 are jour naled between their ends in bearing brackets 37 At each end of the shafts 36 are provided downwardly extending crank arms 38 having stub shafts 39 mounted in journal boxes 40 secured between the flanges 22 and 23 of the side bars 18 of the deck supporting frame 11. The arrangement is such that the deck frame 11 is supported by the shafts 36 atpoints below the fixed hearings in which these shafts rotate and as a result. the deck will rise and fall slightly as the crank shafts 36 rock back and forth.

A back and forth movement is imparted to the deck to promote travel of the materials being treated along the same. and this movement should be such that it will advance the materials along the deck without disturbing the Stratification of the same that is being effected. The materials preferablv are advanced along the deck by suddenh arrest ng the movement of the deck in one directlon so that the momentum imparted to the materials will cause them to slide along the deck slightly after the movement: of the latter has been arrested. Novel means for imparting the desired movement to the deck will nowbe described.

The deck carrying frame 11 is supported by the rock shafts 36 for back and forth In the present casemovement-of the deck supporting frame 11 in the opposite direction is effected by one or more cables, chains or belts 45 (Fig. 1) having one end secured to the frame 11 at 46 and the other end anchored to the fixed frame 10 by an ad justable bolt 47. e Means is provided for tightening the cable 45 to move the deck frame to the left algainst the tension of the springs 41, and for reducing the tension of the cable to permit the frame to be moved in the opposite direction by the springs 41.

In the embodiment of the invention shown in Fig. 1, this is accomplished by providing a drum 48 with one or more cable engaging pulleys 49, and the drum 48 has a central bore adapted to receive rotatably an eccentrio 50 upon the shaft 51. The shaft 51 is journaled in bearings 52 mounted upon the side rails 14 of the fixed frame and the shaft is rotated by the driving wheel 53. The arrangement is such that the cables 4;?) pass around a portion of the pulleys 49, and as the shaft 51 is rotated the drum and pulleys are moved in an orbital path by the eccentric,

in a horizontal direction, while the tensionof the cable is effected only slightly by the movement of the pulleys in the vertical direction. The operating eccentric 50 may be regarded as having a dead center at each end of its stroke where it uses up a period of time during which it neither pulls or releases the cable appreciably. This occurs when the eccentric is substantially on the line A'C of Fig. 1 with the eccentric extending toward A or toward C. At C the deck is at the end of its back stroke (or pull), and at A the cable is slacked ed and the deck is at the end of its forward stroke.

As the eccentric turns from A to G in the clockwise direct-ion it stretches the cable taut and pulls the deck back against the tension of the springs, and the eccentric passes the dead center at C the slowest movement is imparted to the deck and the direction of movement of the deck is changed without shifting the materials upon the .deck surface. As the eccentric continues its movement in .a clockwise direction from C toward A the cable is slacked off and the springs push the deck forward to take up the slack of the cable, and the angular disposition of the crank rocker shafts 36 atthe eginning of the forward movement of the deck assist the springs 41 in moving the deck to the right. l

When.the eccentric reaches the position A the slack is nearly all taken up, but there still remains the final tightening up of the slack. cable which requires a very short period of time, but sufficient for the eccentric to pass slightly below the line AC so that the pulley grips the cable suddenly and begins the next backward pull.. This quick gripping of the cable with its immediate backward pull is the important effect, as it arrests suddenly the movement imparted to the deck by the springs 41 and causes the momentum imparted to the materials to slide them along the. deck surface, at the same time a slight up-throw movement may be impartedto the deck by. the crank arms 38 supporting the same, as will be apparent from Fig. 1 wherein the parts are shown as at the end of the material advancing stroke.

The rotation of the eccentric from its uppermost position toward A may assist some what in increasing the speed at which the cable is slacked off and this promotes a quickened forward stroke. Also the pull againstthe driving means for the eccentric shaft 51 as the eccentric rotates from A toward C helps to slowdown the turn at C. Further the weightof the drum on the rising eccentric as the latter rotating upwardly from C helps to slow down .the turn at G, and the first half of the movement from C toward A is likewise slowed down slightly, while the movement of the eccentric from its uppermost position toward A and about the dead center at'A is speeded up some- What by the weight of the drum.

The quick gripping of the cable and the increasingspeed in the drum moving downwardly in rotating toward A are the important effects, but the twoother results contribute i111producing the desired result, and the combination of all these influences give an eccelerated forward movement 'to the right with quick turn at the forward end-of the stroke, and a slowing backward movement to theleft with a slower turn at the back end of the stroke. This construction it is found imparts a very satisfactory movement to the deck, and is an important improvement .over the deck operating means heretofore employed. The arresting of the movement of the deck in the material advancing direction may be assisted by providing the deck supporting frame 11 with a bumper 54 that may strike against a bracket 55 mounted upon the fixed frame 10, but this is not an essential feature, as the. cable operating means above described is adapted to arrest the movement of the deck sudden enough to produce the desired result. The deck 12 may be variously constructed and is shown as comprising a relatively long hollow casing, that tapers toward the material discharge end, and, is provided with a deck'jsurface 56 supported in spaced relation to'the bottom of the casing. The chamber belowthe deck surface may be divided into different compartments by longitudinally extending partitions 57,'and air may be delivered to the chamber below the deck surface from a fan 58 connected to the wide end of the deck chamber by a hood 59. The fan 58 may be driven from the pulley 6O upon the shaft 51 by a belt 61. I

Thepresent invention contemplates different improvements in the construction of the deck surface 56 which will now be described. i

The deck surface 56 is provided with inclined riflles 62 which extend from the lower side of the deck to the concentrate wall 63 extending along the upper side of the deck, and the materials to be treated are delivered to the deck surface'at one end thereof from the'hopper 64. The deck surface is provided with apertures 65 for the passage of air upwardly therethrough and through the materials upon the deck surface to remove the dust and to promote Stratification of the materials. The deck surface preferably is formed of the individual surface channels 66 placed side by side and which are U-sha-ped in cross section and have upwardly extending sides that form the rifles 62.

. The air passing upwardly through the deck surface, and the movement imparted to the deck cause the materials to spread out rapidly overthe deck surface and to travel lengthwise of the same, and the heavier materials settle quickly and crowd upwardly the lighter materials. As a result the heavier materials will travel along the'riffles and will be guided thereby toward the concentrate wall, while the lighter materials will flow over the top of the rifles laterally toward the lower side of the deck wherethey escape over the discharge board Separation of the materials in accordance with their differences in specific gravity is promotedby causing the lighter materialsto bunch or pile up slightly along the rifles and then flow laterally over the rifles toward the tailing discharge side of the deck. In the present case this bunching or piling up of the materials is promoted by providing the rifles at intervals with sections 68 that are slightly higher than the remaining portions of the rifles. These raised sections may be provided over the deck surface at intervals in a more or less staggered arrangement to bunch the flow of the materials whenever it may be desired. As a result the materials traveling along a rifle behind a raised section 68 will not flow laterally over the rifle until they pass out from behind the section 68 whereupon they will flood. over the rifle, in this manner a series of accumulations of the light materials are formed behindthe sections at intervals over the deck surface and they flood over the rifles as they escape from behind the sections. The sections 68 need he only slightly higher than the remaining portion of the rifles, and may be several inches long to cause suflicient materials to accumulate behind the same to flood over one or more rifles upon escaping therefrom.

In addition to providing the sections 68 back of which the lighter materials may accumulate, it may be desirable to promote bunching of the materials traveling along the rifles to cause the lighter materials to flow'over the rifles as they approach the concentrate wall. In the present case this is accomplished by increasing the slope of the deck surface adjacent the concentrate wall as at 69, Fig. 5. From this view it will be seen that the portion of the deck surface extending alongthe concentrate wall 63 is bent upwardly slightly so that the materials traveling along therifles toward the concentrate wall will pile up upon reaching this wall" thereby to increase the cross flow of the lighter materials.

Another feature of the present invention resides in the disposition of the apertures 65 within the deck surface. The Stratification of the materials is an important part of the separating operation, and this is produced by air passing upwardly through the materials upon the deck surface, and also by the movement imparted to the deck.

It is found that the fine particles of the heavier materials or values are often carried up by the air passing upwardly through i the deck surface. This is not desired as these fine values may be carried off with the lighter materials or tailings. To prevent this the deck surfaces may be provided with portions where the perforations 65 are omitted, and the deck surface may be provided with other portions where the perforations are opened very slightly. In Fig. 8 the deck is shown as having the perforations omitted along the-lower side of the deck and from a portion of the delivery end of the deck, and the portions or patches where the perforations are nearly or entirely closed are indicated as lying within the dotted enclosures indicated by X.

Passing the materials being treated over a dead air space formed by omitting the crforations, or other portions of the eck where the air currents are reduced, gives the fine values a chance to sift back down to the deck surface under the influence of the deck movement, and as the fine values are heavier they will settle more rapidly than the lighter particles and prevent the latter from reaching the lower strata. The preferred position of the portions X of slight air currents is near the ends of the raised portions 68 of the rifles; that is near the points where the flooding of thematerials at the ends of the raised portions occur where they give the material an opportunity to re stratify. The apertures 65 within the deck surface preferably are provided with lips 70, see Fig. 11, which serve to direct the air as it passes through the apertures. The amount of air passing upwardly throu h the portion X of the deck surface may e tween the arm and deck frame consists of a link 73 fastened to the frame 11 by a bolt 7 roller 84 and then to the bolt 78.

74, and the link is adjustably secured to the arm by a bol-t having adjusting nuts engaging the opposite faces of this arm. The operating cable 7 6 has one end secured to the operating arm 71 by a bolt 77 and the other end of the cable is anchored to the fixed frame by an adjustable bolt 7 8. The cable 76 passes around an ordinary pulley 79 mounted on a shaft 80 supported by brackets 81. The cable then passes around thepulley 82 mounted on the eccentric shaft 83 similar to the eccentric shaft 50 above described, and the shaft 83, is rotated by a pulley or other means not shown. The cable then passes downwardly about an idle The construction is such that as the eccentric shaft 83 is rotated it will tension and slack off the cable ,similar tothe pulleys 49 above described, and as the cable is pulled taut it will rock thearm 71 to the left and pull the deck frame 11 in the same direction against the tension of the spring 41. As

the pulley 82 is moved awa fromthe cable by its eccentric the cable w ll be slacked off and the deck frame 11 will move to the right under thetension of the spring 41, andas'the deck approaches the end of its stroke in this directlon it may he suddenly arrested b the arm 71 striking against an abutment racket 85. Resilient material 86 may be provided upon the arm and bracket respectively at the oint of contact, and the position of the doc when the bump occurs may be varied by adjusting the nuts upon the bolt 7 5.

It may be desirable to rovide means for taking up the slack in t e cable 76 as the tension of the same is reduced by the rotating eccentric, and in the construction shown in Fig. 9 a coiled spring 87 is provided for exerting a pull in a lateral direction upon the cable 76. The spring 87 has one end secured to the cable at 8 8 and the other end of the spring is adjustably se cured to a bracket 89. The extent to which the cable 76 will be deflected laterally by the spring 87 may be limited by a strap 90 secured to the cable at 88 and extending from the cable in a direction opposite to the sprin 87, and the opposite end of this strap may e adjustably secured to a bracket 91. The stren th of the spring 87 should be. much less t an the strength of the spring or springs ll. that move thedeck in one direction.

Still a difierent arrangement of the deck operatin cable is shown in Fig. 10 wherein the n does not pass around the pulley or sheave 92 upon the cam shaft 93 but merely rests upon the 11 per face of this pulley. As a result of this construction the lower run of the cable 94: passin from the lower side of the pulle 95 to t e sto 98 will be deflected upwar ly as the cam aft 93 rotates, and this will tighten the cable .to pull the deck frame 11 to the left. In

up the slack between the portion of the cable extending from the wheel to the deck.

What is claimed is:

1. A concentrator table comprising, in combination, a deck having means for supporting the same, a deck surface having riflies extending over the same and apertures between the riflies for the passage of air upwardly through the deck surface, and the deck surface having sections between the riflles where I the apertures are practically closed to provide dead air spaces at saidsections and which are surrounded by sections having apertures of substantial opening.

2. A concentrator table comprising, in combination, a deck having means for supporting the same, a deck surface having rifiles extending over the same and having apertures between the rifles for the passage of air upwardly through the deck surface, lips extending upwardly in aninclined direction from the apertures to direct the air passing through the apertures, and the deck surface havingsections between the rifiles where the apertures are practically closed to provide dead air spaces at said sections and which are surrounded by sections having apertures of substantial opening.

-3. A concentrator table comprising, in combination, a deck having means for supporting the same at a transverse inclination, a deck surface, rilfies extending across the surface for directing the heavier materials along the rifiles while the lighter materials pass laterally over the top of the riffles, upstanding portions upon the riflles at intervals over the deck surface and forming sections of increased height against which the materials may accumulate and then flood over the rifles as they pass from behind the raised sections, and the deck surfacehaving apertures formed therein between the riftles for the passage of air upwardly therethrough and having areas where the apertures are practicallv closed to provide dead air spaces surroun ed by areas havin agertures of substantial openings, an t e dead air spaces being located to promote retion over the deck surface toward the concentrate wall, and a narrow portion of the deck surface extending along the upper side of the deck and over which the rililes extend being bentupwardly slightly at an increased angle to increase the slope of the deck surface adjacent the upper side of the deck to increase the iling up of the material between the riflles as they approach the concentrate wall.

5. A deck for a dry concentrator table comprising, in combination, a deck surface having apertures therein for the passage of air upwardly therethrough and having a concentrate wall extending along one side,

rifiles extendin in an inclined direction over.

the deck surface toward the concentrate wall,'and a narrow portion of the deck surface extending along the side of the deck adjacent the concentrate wall and over which the rifiies extend being inclined u wardly slightly relative to the rest of t e deck surface to produce an up-slope that increases the piling up of the materials be-' tween the rifiles as they approach the concentrate wall.

6. A concentrator table comprising, in combination, a deck having means for supporting it at a transverse inclination, a deck surface, riflles extending across the surface for directin the heavier materials along the riflles w ile the lighter materials flow laterally over the riffles, raised portions extending upwardl from the rifiies at intervals over the dec surface and forming sections of increased height against which the materials may accumulate and then flood over the riftles as the pass from behind the sections, and the decr surface having aper-- tures formed therein between the riflles for the passage of air upwardly therethrough and having areas between tie rifiies where the-apertures are practically closed to provide dead air spaces located relative to the points where the materials escape from behind the sections to give the materials an opportunity to r e-stratify at said points.

7. In a concentrator table, in combination,-

clamping the spaced brackets rigidly against the opposite faces of the intermediate bracket, and the spaced brackets being adapted to receive in the space between them a block forming an abutment for the inner end of the intermediate bracket.

- 8. In a concentrator table, in combination, a deck supporting-frame, a deck mounted thereupon for adjustment to different transverse inclinations, hinge means between the frame and deck for supporting one side of the deck, and clamping means for rigidly securing the opposite side of the deck to the frame in different positions of angular adjustment, including brackets secured to the deck and frame respectively for overlapping engagement with each other, a third bracket mounted in spaced relation to one of said brackets .to receive the projecting portion of the remaining bracket between them in difierent positions of adjustment, and means for clamping the spaced brackets rigidly against the opposite faces of the intermediate bracket.

9. concentrator table comprising, in combination a deck supportin frame having a deck thereupon, a fixed frame provided with a bearing-for a shaft, a shaft journaled in said bearing and having downwardly extending crank arms at its opposite ends, and bearings secured rigidly to the deck frame and having the lower ends of the crank arms journaled in the bearing movably to support the deck frame suspended from the fixed frame by the downwardly extending crank arms.

10. A concentrator table comprising, in combination,-a deck supporting frame having a deck thereupon, a fixed frame provided with bearings for receiving shafts extending transversely of the frame, shafts journaled in said bearings and having downwardly extending crank arms at their opposite ends, and bearings secured rigidly to the deck frame and having the lower ends of the crank arms journaled in the bearings movably to support the deck frame suspended from the fixed frame by the downwardly extending crank arms.

11. A concentrator table comprising,.in combination, a deck having means for supporting the same, a deck surface having riflles extending over the same and apertures betweenv the riflies for the passage of air upwardly through the deck surface, and the deck surface having sections distributed over the same and having the openin s of the apertures substantially reduced within said sections. I

In testimony whereof, I have signed my name to this specification.

ALBERT H. STEBBINS, 

